The structure of tined devices commonly known as rakes is both familiar and has long been known. Conventional rakes, while adequate for the accumulation or gathering of material such as leaves or grass clippings, experience tremendous efficiency problems as a result of such accumulation. That is, the user must either cease raking operations and remove the accumulated pile of material by another means or, in the alternative, exert a sufficiently large pressure on the rake to move the entire mass of accumulated material along the surface to be raked. The pressure required to move such a mass of material results in individual tines bending or breaking at the root end of the tines; that is, at the end where the tines are attached to the rake head. Because these ends of the tines, and the adjacent end of the rake head, are highly stressed by the pressure exerted by a user to move a pile, it is not infrequently that tines will break completely from the rake head and that the rake head itself will become weakened and cracked. The rake of the present invention is directed to this problem.
In an example typical of the prior art. U.S. Pat. No. 3,724,188 to H. O. Eads shows a rake having a conventional tined rake head formed of polypropylene to be lighter than other conventional steel or bamboo tined rakes. The rake head is strengthened by ribs, but there is no suggestion of any means which facilitate and increase efficiency of handling or moving a pile of material accumulated during a raking operation without damaging the tines or rake head.
U.S. Pat. No. 1,591,738 to C. H. Bell shows a garden-type rake having an elongated, bar-like rake head of small dimensional cross section with relatively short, rigid teeth extending from this head. To adapt such a rake for gathering lighter articles such as leaves, a flanged channel bar fits over the rake head and a set of flat spring teeth is secured to the channel bar. The spring teeth extend forwardly of the normal rigid teeth of the rake, and the distance between the rigid and spring teeth is not sufficient to permit a substantial pile of material to accumulate between the two sets of teeth. Instead, both sets of teeth engage a surface to be raked to provide an enhanced raking action, and the force developed from both sets of teeth is applied to the bar-like rake head. While this rake and attachment may easily gather a layer of leaves from the ground, it is incapable of containing and moving a pile of leaves during a raking operation, as the leaves would pour over the upper surface of the rake head, the bar and the spring teeth.
U.S. Pat. Nos. 3,332,223 and 4,351,145 disclose tined rakes which have multiple sets or double rows of tines to increase the material gathering efficiency of the rakes. However, the prior art rakes fail to incorporate any structure for efficiently handling piles of accumulated material without unduly stressing the tines or the areas of the rake head where the tines are attached.
Clearly, despite a long history of rake development, the problem of providing a rake which enables the containment and moving of accumulated material efficiently, without interrupting the raking operation and without damaging or weakening the tines and rake head, has never been addressed.